Apparatus and systems for flood/moisture detection and notification

ABSTRACT

A monitoring apparatus includes a rigid structure, at least one sensor supported by the structure that is configured to detect a level of liquid or a presence of moisture in a vicinity of the structure, and a housing supported by the structure. A transmitter and a controller are located within the housing. The controller is in electrical communication with the at least one sensor and the wireless transmitter, and the controller is configured to cause the transmitter to transmit measurement data received from the at least one sensor to a remote device.

FIELD OF THE INVENTION

The present invention relates generally to sensors and, moreparticularly, to environmental sensors.

BACKGROUND OF THE INVENTION

Electric utility assets, such as substations, are often located in areasthat are less desirable for other uses. These areas may be low-lyingareas adjacent to rivers and streams and which may be subjected toflooding. For example, flooding at a substation may damage high voltageequipment and may require de-energization of the entire substation.Because substations are generally unattended, electric utilitiestypically send personnel out to monitor for flooding during storms.Unfortunately, this practice may be expensive and may subject personnelto dangerous conditions.

SUMMARY

It should be appreciated that this Summary is provided to introduce aselection of concepts in a simplified form, the concepts being furtherdescribed below in the Detailed Description. This Summary is notintended to identify key features or essential features of thisdisclosure, nor is it intended to limit the scope of the invention.

According to some embodiments of the present invention, a monitoringapparatus includes a rigid structure, at least one sensor supported bythe structure that is configured to detect a level of liquid or apresence of moisture in a vicinity of the structure, and a housingsupported by the structure. Exemplary sensors may include float sensors,ultrasonic sensors, radar sensors, lidar sensors, moisture sensors, etc.A transmitter (wired or wireless) and a controller are located withinthe housing. The controller is in electrical communication with the atleast one sensor and the transmitter, and the controller is configuredto cause the transmitter to transmit data received from the at least onesensor to a remote device. The controller may also be configured togenerate an alert or notification that is transmitted to personneland/or to equipment. For example, in some embodiments, the alert couldtrigger not only human intervention but also command various equipmentto perform a function. For example, equipment such as pumps, valves,motors, etc., may be commanded to turn on and/or off, change currentoperational status, etc. A door may be commanded to close and/or open.Various electrical equipment may be commanded to de-energize and/orre-energize, etc.

In some embodiments, the rigid structure is configured to be mounted onor in the ground, such as a pipe or post. In other embodiments, thestructure is configured to be mounted to another structure.

In some embodiments, the at least one sensor includes a first sensor anda second sensor in vertically spaced apart relationship on thestructure. For example, in some embodiments, the first sensor issupported by the structure so as to be located at least approximatelysix inches (6″) above the ground, and the second sensor is supported bythe structure so as to be located at least approximately eighteen inches(18″) above the ground. The first or lower sensor can identify thebeginning of a flood situation in the vicinity and an early warning canbe issued. The second or upper sensor can identify when flood water hasreached a hazardous level. In addition, the use of two sensors invertical, spaced-apart relationship allows for the calculation of therate of rise of flood water, as well as the rate that flood water isreceding.

In some embodiments, the monitoring apparatus includes a power sourcethat is configured to supply power to the at least one sensor, thecontroller, and the transmitter. Exemplary power sources may include abattery, a solar power source and rechargeable battery for storingexcess solar energy, and an energy harvesting circuit comprisinggraphene or station AC service. In other embodiments, the at least onesensor, the controller, and the transmitter are configured to receiveelectrical power from an external AC or DC power source.

In some embodiments, the monitoring apparatus further includes an imagesensor (e.g., visual or infrared) configured to capture image data froma vicinity of the structure. The controller is in electricalcommunication with the image sensor and is configured to cause thetransmitter to transmit image data received from the image sensor to theremote device.

In some embodiments, the monitoring apparatus may include additionalsensors, such as a liquid flow sensor, a moisture sensor, an anemometer,a temperature sensor, a humidity sensor, a noise sensor, an air qualitysensor, etc.

According to other embodiments of the present invention, a monitoringapparatus includes a rigid structure configured to be mounted on or inthe ground, a first sensor and a second sensor supported by thestructure in vertically spaced apart relationship, and a housingsupported by the structure. The first and second sensors are configuredto measure a level of liquid in a vicinity of the structure. Atransmitter (wired or wireless) and a controller are located within thehousing. The controller is in electrical communication with the firstand second sensors and the transmitter, and the controller is configuredto cause the transmitter to transmit measurement data received from thefirst and second sensors to a remote device. In addition, the controlleris configured to determine a rate of rise of liquid near the structureand to cause the transmitter to transmit the rate of rise data to theremote device. The controller may also be configured to determine a rateat which liquid is receding (e.g., receding flood water) near thestructure and to cause the transmitter to transmit the receding rate tothe remote device. The monitoring apparatus also includes a power sourceconfigured to supply power to the first and second sensors, thecontroller, and the transmitter.

According to other embodiments of the present invention, a monitoringsystem includes a monitoring apparatus, comprising at least one wirelesssensor and at least one wireless node in a vicinity of the at least onewireless sensor that receives data from the at least one wirelesssensor. For example, the at least one wireless sensor may be configuredto measure a level of liquid in a vicinity of the monitoring apparatusand transmit liquid level data to the at least one wireless node. The atleast one wireless node is configured to receive the liquid level datafrom the at least one wireless sensor and to transmit the liquid leveldata to a remote device. Exemplary wireless sensors include floatsensors, ultrasonic sensors, radar sensors, lidar sensors, etc. The atleast one wireless node may also be configured to transmit a command toequipment in a vicinity of the monitoring apparatus to perform afunction. For example, equipment such as pumps, valves, motors, etc.,may be commanded to turn on and/or off, change current operationalstatus, etc. A door may be commanded to close and/or open. Variouselectrical equipment may be commanded to de-energize and/or re-energize,etc.

Embodiments of the present invention are advantageous because time andcost associated with monitoring substations and other electric utilityassets can be reduced, while also increasing customer reliability.Monitoring apparatus and systems according to embodiments of the presentinvention allow for rerouting of power flow for extreme high voltageassets, such as transmission substations, when flood conditions exist.Moreover, because remote monitoring is possible, personnel safety isincreased. In addition, monitoring apparatus and systems according toembodiments of the present invention can alert authorized personnel whenflood waters have receded to a safe level to restore power to equipment.Monitoring apparatus and systems according to embodiments of the presentinvention can also be configured to restore power to equipmentautomatically and without the requirement of human intervention.

It is noted that aspects of the invention described with respect to oneembodiment may be incorporated in a different embodiment although notspecifically described relative thereto. That is, all embodiments and/orfeatures of any embodiment can be combined in any way and/orcombination. Applicant reserves the right to change any originally filedclaim or file any new claim accordingly, including the right to be ableto amend any originally filed claim to depend from and/or incorporateany feature of any other claim although not originally claimed in thatmanner. These and other objects and/or aspects of the present inventionare explained in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which form a part of the specification,illustrate various embodiments of the present invention. The drawingsand description together serve to fully explain embodiments of thepresent invention.

FIG. 1 illustrates a monitoring apparatus according to some embodimentsof the present invention in an installed configuration.

FIG. 2 is a perspective view of a monitoring apparatus according to someembodiments of the present invention.

FIG. 3 is an enlarged view of one of the sensors of the monitoringapparatus of FIG. 2.

FIG. 4 is an enlarged view of the housing of the monitoring apparatus ofFIG. 2.

FIG. 5 illustrates the housing of FIG. 4 with a panel removed toillustrate an internal portion of the housing.

FIG. 6 illustrates a monitoring system according to some embodiments ofthe present invention.

FIG. 7 is a schematic illustration of the sensors and electroniccomponents of the monitoring apparatus of FIG. 2, according to someembodiments of the present invention.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter withreference to the accompanying figures, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Like numbers refer to like elementsthroughout. In the figures, certain components or features may beexaggerated for clarity, and broken lines illustrate optional featuresor operations unless specified otherwise. In addition, the sequence ofoperations (or steps) is not limited to the order presented in thefigures and/or claims unless specifically indicated otherwise. Featuresdescribed with respect to one figure or embodiment can be associatedwith another embodiment or figure although not specifically described orshown as such.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the specification andrelevant art and should not be interpreted in an idealized or overlyformal sense unless expressly so defined herein. Well-known functions orconstructions may not be described in detail for brevity and/or clarity.

When an element is referred to as being “connected”, “coupled”,“responsive”, or variants thereof to another element, it can be directlyconnected, coupled, or responsive to the other element or interveningelements may be present. In contrast, when an element is referred to asbeing “directly connected”, “directly coupled”, “directly responsive”,or variants thereof to another element, there are no interveningelements present. Like numbers refer to like elements throughout.Furthermore, “coupled”, “connected”, “responsive”, or variants thereofas used herein may include wirelessly coupled, connected, or responsive.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. Well-known functions or constructions may not be described indetail for brevity and/or clarity. The term “and/or” includes any andall combinations of one or more of the associated listed items.

As used herein, the terms “comprise”, “comprising”, “comprises”,“include”, “including”, “includes”, “have”, “has”, “having”, or variantsthereof are open-ended, and include one or more stated features,integers, elements, steps, components or functions but does not precludethe presence or addition of one or more other features, integers,elements, steps, components, functions or groups thereof. Furthermore,as used herein, the common abbreviation “e.g.,” which derives from theLatin phrase “exempli gratia,” may be used to introduce or specify ageneral example or examples of a previously mentioned item, and is notintended to be limiting of such item. The common abbreviation “i.e.,”which derives from the Latin phrase “id est,” may be used to specify aparticular item from a more general recitation.

It will be understood that although the terms first, second, third, etc.may be used herein to describe various elements/operations, theseelements/operations should not be limited by these terms. These termsare only used to distinguish one element/operation from anotherelement/operation. Thus, a first element/operation in some embodimentscould be termed a second element/operation in other embodiments withoutdeparting from the teachings of present inventive concepts. The samereference numerals or the same reference designators denote the same orsimilar elements throughout the specification.

The terms “about” and “approximately”, as used herein with respect to avalue or number, means that the value or number can vary by +/−twentypercent (20%).

Referring to FIGS. 1 and 2, a monitoring apparatus 10 according to someembodiments of the present invention is illustrated. The monitoringapparatus 10 includes a rigid structure 12, such as a post or pipe, thatis configured to be mounted in the ground (FIG. 1). The illustratedstructure 12 includes an above-ground portion 14 and a below-groundportion 16, as illustrated in FIG. 2. The below ground portion 16 of thestructure 12 is configured to be embedded, for example, within concretein order to withstand strong water currents. In some embodiments, thestructure 12 may be a pipe, such as a polyvinyl chloride (PVC) pipe.However, embodiments of the present invention are not limited to thestructure 12 being a PVC pipe. Structures of various configurations andof various materials may be utilized including other polymericmaterials. Typically, any material that is resistant to corrosion anddegradation from the elements may be utilized.

An exemplary pipe that can serve as the structure 12 for the monitoringapparatus 10 may be a four inch (4″) diameter, schedule 80 PVC pipe witha lower portion 16 approximately one to three feet (1′-3′) in length andan upper portion 14 approximately two to four feet (2′-4′) in length.However, various sizes and lengths of pipe may be utilized. Embodimentsof the present invention are not limited to any particular length of thestructure 12. Structures of various lengths as well as configurationsmay be utilized.

Embodiments of the present invention are not limited to having astructure 12 embedded within concrete. In some embodiments, thestructure 12 may be embedded directly within the ground without the useof concrete as long as the structure remains resistant to movementcaused by strong water currents. In other embodiments, a rigid structuremay be configured to be attached to another structure, such as a powerpole, tower, or other structure that would be resistant to strong watercurrents.

The illustrated monitoring apparatus 10 includes a first sensor 20 and asecond sensor 22 secured in vertically spaced apart relationship to theabove-ground portion 14 of the structure 12. The first and secondsensors 20, 22 are configured to detect and measure a water (or otherliquid) level in a vicinity of the structure 12. In addition to beingused to detect flooding, a monitoring apparatus 10 according toembodiments of the present invention may be used to detect the presenceof other liquids, such as oil (e.g., oil spills). For example, amonitoring apparatus 10 may be used in an oil stop valve (OSV) vault todetect oil leaks within the vault for environmental compliance.

Exemplary sensors for the first and second sensors 20, 22 include, butare not limited to, float sensors, ultrasonic sensors radar sensorslidar sensors, etc. In the illustrated embodiment, the first and secondsensors 20, 22 are mechanical float sensors. For example, referring toFIG. 3, each illustrated sensor 20, 22 includes a bracket 23 that issecured to the structure 12 and a float 24 movably supported by thebracket 23. The float 24 is configured to float on top of a liquidsurface and, as the liquid level goes up or down, the float movesvertically with the liquid level. The float opens or closes a switch asit moves upwardly with a rising liquid level, and the switch provides asignal to the controller 42 (FIG. 7) indicating an identified liquidlevel at the monitoring apparatus location.

In some embodiments, the first sensor 20 is supported by the structure12 so as to be located approximately four to six inches (4″-6″) abovethe ground, and the second sensor 22 is supported by the structure 12 soas to be located approximately twelve to eighteen inches (12″-18″) abovethe ground. However, embodiments of the present invention are notlimited to these dimensions. The sensors 20, 22 may each be located atvarious other elevations above ground level.

The use of two sensors 20, 22 is advantageous because the first or lowersensor 20 can identify the beginning of a flood event in the vicinity ofthe monitoring apparatus 10, and an early warning can be issued. Thesecond or upper sensor 22 can identify when a flood level has reached adangerous level. For example, when the monitoring apparatus 10 is usedin a substation location, the second or upper sensor 22 can identifywhen a water level has become an imminent threat to energized equipment.In addition, the use of two sensors 20, 22 allows for additionalfunctionality such as calculating the rate of rise of flood water (orother liquid), as well as the rate that flood water (or other liquid) isreceding.

The illustrated monitoring apparatus 10 also includes a housing 30supported by the structure 12. Although illustrated at the upper end 12a of the structure 12, the housing 30 may be secured to other portionsof the post 12, as well. Embodiments of the present invention are notlimited to the illustrated location or configuration of the housing 30.Located within the housing 30 are various electronic components of themonitoring apparatus 10. For example, FIG. 5 illustrates the housing 30with a panel 32 removed to illustrate one of the electronic componentsinside. The housing 30 is configured to protect the electroniccomponents therewithin from the environment and is preferably sealed tokeep moisture out.

In some embodiments, located within the housing 30 are a transmitter 40(e.g., a wireless or wired transmitter) and controller 42, asillustrated in FIG. 7. The controller 42 is in electrical communicationwith the first and second sensors 20, 22 and the transmitter 40. Thecontroller 42 is configured to cause the transmitter 40 to transmitmeasurement data received from the first and second sensors 20, 22 to aremote device, such as a remote computer or smart phone. For example,upon the first sensor 20 detecting a rise in water level, the firstsensor 20 provides a signal to the controller 42 and the controller 42causes the transmitter 40 to transmit water level information to aremote device, such as a smart phone, a computer in an operations centerof an electric utility, etc. Exemplary transmission formats include, butare not limited to, email, text messaging, MQTT (Message QueuingTelemetry Transport), etc. Similarly, upon the second sensor 22detecting a rise in water level, the second sensor 22 provides a signalto the controller 42 and the controller 42 causes the transmitter 40 totransmit water level information to the remote device.

In addition, the controller 42 may be configured to generate andtransmit, via the transmitter 40, various alerts or notifications. Suchalerts/notifications may trigger not only human intervention but mayalso command various types of equipment in a vicinity of the monitoringapparatus to perform one or more functions. For example, equipment(e.g., pumps, valves, etc.) may be commanded to turn on and/or off,change operational status, etc. A door may be commanded to close and/oropen. Various electrical equipment may be commanded to de-energizeand/or re-energize, etc.

The electronics of the monitoring apparatus 10 are powered by a powersource 44 (FIG. 7). Exemplary power sources may include a battery, asolar power source and rechargeable battery for storing excess solarenergy, and an energy harvesting circuit comprising a perpetuallyoscillating source, such as graphene. In other embodiments, the powersource may be an external power source, such as an external AC or DCpower source.

In some embodiments, the monitoring apparatus 10 may include one or moreadditional sensors 46 (FIG. 7). The controller 42 is in electricalcommunication with the additional sensor(s) 46 and is configured tocause the transmitter 40 to transmit data received from the additionalsensor(s) 46 to a remote device. For example, in some embodiments, themonitoring apparatus 10 may include a liquid flow sensor or a moisturesensor. An exemplary location for a monitoring apparatus 10 with amoisture sensor is a relay cabinet, a cable tray, etc. In otherembodiments, the monitoring apparatus 10 may include an image sensorthat is configured to capture image data of a vicinity of the monitoringapparatus 10. The controller 42 is in electrical communication with theimage sensor and is configured to cause the transmitter 40 to transmitimage data received from the image sensor to a remote device. Forexample, upon detecting a flood condition via the first sensor 20, animage sensor may be configured to capture an image of the floodcondition and this image can be transmitted to a remote device withwater level data. In other embodiments, an infrared sensor may beutilized to detect heat signatures, for example of people and animals.

Referring to FIG. 6, a monitoring system 100 according to someembodiments of the present invention is illustrated. The monitoringsystem 100 includes a monitoring apparatus 10 and one or more wirelessnodes 120 in a vicinity of the at monitoring apparatus 10. Althoughmultiple wireless nodes 120A, 120B, 120C, 120N are illustrated in FIG.6, the monitoring system 100 can have any number of wireless nodes,including a single wireless node. The illustrated monitoring apparatus10 includes first and second wireless sensors 20, 22 configured tomeasure a level of liquid in a vicinity of the monitoring apparatus 10and to transmit liquid level data to the wireless nodes 120. Eachwireless node is configured to receive the liquid level data from thewireless sensors 20, 22 and to transmit the liquid level data to aremote device, such as a smart phone, a computer in an operations centerof an electric utility, etc. Exemplary wireless sensors 20, 22 includefloat sensors, ultrasonic sensors, radar sensors, lidar sensors, etc.Although two wireless sensors 20, 22 are illustrated, a monitoringdevice may have various numbers of sensors, including a single sensor.Moreover, the monitoring apparatus 10 may have sensors other than liquidlevel sensors, such as a liquid flow sensor, a moisture sensor, an imagesensor, etc.

In some embodiments, the monitoring apparatus 10 may not include liquidlevel sensors, but may include only other types of sensors. For example,the monitoring apparatus 10 may include a moisture sensor and may beconfigured to be located within an electronic device enclosure, a cabletray, etc. In some embodiments, one or more weather sensors may beincluded, such as an anemometer, a temperature sensor, a humiditysensor. Moreover, other sensors such as noise sensors and air qualitysensors may be utilized.

In some embodiments, a wireless node 120 may be configured to generateand transmit various alerts or notifications. Such alerts/notificationsmay trigger not only human intervention but also command various typesof equipment in a vicinity of the monitoring apparatus to perform one ormore functions. For example, equipment (e.g., pumps, valves, etc.) maybe commanded to turn on and/or off. A door may be commanded to closeand/or open. Various electrical equipment may be commanded tode-energize and/or re-energize, etc.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. Although a few exemplary embodiments ofthis invention have been described, those skilled in the art willreadily appreciate that many modifications are possible in the exemplaryembodiments without materially departing from the teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe claims. The invention is defined by the following claims, withequivalents of the claims to be included therein.

That which is claimed is:
 1. A monitoring apparatus, comprising: a rigidstructure; at least one sensor supported by the structure and configuredto detect a level of liquid in a vicinity of the structure; a housingsupported by the structure; a transmitter within the housing; and acontroller within the housing, wherein the controller is in electricalcommunication with the at least one sensor and the transmitter, whereinthe controller is configured to determine a rate of rise of the liquid,and wherein the controller is configured to cause the transmitter totransmit rate of rise data and data received from the at least onesensor to a remote device.
 2. The monitoring apparatus of claim 1,wherein the rigid structure is configured to be mounted on or in ground.3. The monitoring apparatus of claim 2, wherein the structure comprisesa pipe or post.
 4. The monitoring apparatus of claim 1, wherein therigid structure is configured to be mounted to another structure.
 5. Themonitoring apparatus of claim 1, wherein the at least one sensorcomprises a first sensor and a second sensor in vertically spaced apartrelationship.
 6. The monitoring apparatus of claim 5, wherein the firstsensor is supported by the structure so as to be located approximatelysix inches (6″) above ground, and wherein the second liquid level sensoris supported by the structure so as to be located approximately eighteeninches (18″) above the ground.
 7. The monitoring apparatus of claim 1,wherein the at least one sensor comprises a float sensor, an ultrasonicsensor, a radar sensor, a lidar sensor, or a moisture sensor.
 8. Themonitoring apparatus of claim 1, further comprising a power sourceconfigured to supply power to the at least one sensor, the controller,and the transmitter.
 9. The monitoring apparatus of claim 8, wherein thepower source comprises a battery.
 10. The monitoring apparatus of claim8, wherein the power source comprises: a solar power source; and arechargeable battery for storing excess solar energy.
 11. The monitoringapparatus of claim 8, wherein the power source comprises an energyharvesting circuit comprising graphene.
 12. The monitoring apparatus ofclaim 1, wherein the at least one sensor, the controller, and thetransmitter are configured to receive electrical power from an externalAC or DC power source.
 13. The monitoring apparatus of claim 1, furthercomprising an image sensor configured to capture image data of avicinity of the structure, wherein the controller is in electricalcommunication with the image sensor and is configured to cause thetransmitter to transmit image data received from the image sensor to theremote device.
 14. The monitoring apparatus of claim 1, furthercomprising at least one additional sensor supported by the structure,wherein the at least one additional sensor comprises one or more of thefollowing: a liquid flow sensor, a moisture sensor, an anemometer, atemperature sensor, a humidity sensor, a noise sensor, an air qualitysensor.
 15. The monitoring apparatus of claim 1, wherein the controlleris configured to cause the transmitter to transmit a command toequipment in a vicinity of the monitoring apparatus to perform afunction.
 16. A monitoring apparatus, comprising: a rigid structureconfigured to be mounted on or in ground; a first sensor and a secondsensor supported by the structure in vertically spaced apartrelationship, wherein the first and second sensors are configured todetect a level of liquid in a vicinity of the structure; a housingsupported by the structure; a transmitter within the housing; acontroller within the housing, wherein the controller is in electricalcommunication with the first and second sensors and the transmitter,wherein the controller is configured to determine a rate of rise of theliquid, and wherein the controller is configured to cause thetransmitter to transmit rate of rise data and data received from thefirst and second sensors to a remote device; and a power sourceconfigured to supply power to the first and second sensors, thecontroller, and the transmitter.
 17. The monitoring apparatus of claim16, wherein the power source comprises a battery.
 18. The monitoringapparatus of claim 16, wherein the power source comprises: a solar powersource; and a rechargeable battery for storing excess solar energy. 19.The monitoring apparatus of claim 16, further comprising at least oneadditional sensor supported by the structure, wherein the at least oneadditional sensor comprises one or more of the following: a liquid flowsensor, a moisture sensor, an anemometer, a temperature sensor, ahumidity sensor, a noise sensor, an air quality sensor.
 20. Themonitoring apparatus of claim 16, wherein the controller is configuredto cause the transmitter to transmit a command to equipment in avicinity of the monitoring apparatus to perform a function.
 21. Amonitoring system, comprising: a monitoring apparatus, comprising atleast one wireless sensor configured to detect a level of liquid in avicinity of the monitoring apparatus and a rate of rise of the liquid,and transmit liquid level data and rate of rise data, wherein the atleast one wireless sensor comprises a float sensor, an ultrasonicsensor, a radar sensor, a lidar sensor, or a moisture sensor; and atleast one wireless node in a vicinity of the at least one wirelesssensor, the at least one wireless node configured to receive the datafrom the at least one wireless sensor and to transmit the data to aremote device.
 22. The monitoring system of claim 21, wherein the atleast one wireless node is configured to transmit a command to equipmentin a vicinity of the monitoring apparatus to perform a function.